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Torii S, David SC, Larivé O, Cariti F, Kohn T. Observed Kinetics of Enterovirus Inactivation by Free Chlorine Are Host Cell-Dependent. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:18483-18490. [PMID: 36649532 DOI: 10.1021/acs.est.2c07048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Virucidal efficacies of disinfectants are typically assessed by infectivity assay utilizing a single type of host cell. Enteroviruses infect multiple host cells via various entry routes, and each entry route may be impaired differently by a given disinfectant. Yet, it is unknown how the choice of host cells affects the observed inactivation kinetics. Here, we evaluated the inactivation kinetics of echovirus 11 (E11) by free chlorine, ultraviolet (UV) irradiation, and heat, using three different host cells (BGMK, RD, and A549). Inactivation rates were independent of the host cell for treatment of E11 by UV or heat. Conversely, E11 inactivation by free chlorine occurred 2-fold faster when enumerated on BGMK cells compared with RD and A549 cells. Host cell-dependent inactivation kinetics by free chlorine were also observed for echovirus 7, 9, and 13, and coxsackievirus A9. E11 inactivation by free chlorine was partly caused by a loss in host cell attachment, which was most pronounced for BGMK cells. BGMK cells lack the attachment receptor CD55 and a key subunit of the uncoating receptor β2M, which may contribute to the differential inactivation kinetics for this cell type. Consequently, inactivation kinetics of enteroviruses should be assessed using host cells with different receptor profiles.
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Affiliation(s)
- Shotaro Torii
- Laboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015Lausanne, Switzerland
| | - Shannon Christa David
- Laboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015Lausanne, Switzerland
| | - Odile Larivé
- Laboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015Lausanne, Switzerland
| | - Federica Cariti
- Laboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015Lausanne, Switzerland
| | - Tamar Kohn
- Laboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015Lausanne, Switzerland
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Saguti F, Kjellberg I, Churqui MP, Wang H, Tunovic T, Ottoson J, Bergstedt O, Norder H, Nyström K. The Virucidal Effect of the Chlorination of Water at the Initial Phase of Disinfection May Be Underestimated If Contact Time Calculations Are Used. Pathogens 2023; 12:1216. [PMID: 37887732 PMCID: PMC10609707 DOI: 10.3390/pathogens12101216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 09/27/2023] [Accepted: 09/29/2023] [Indexed: 10/28/2023] Open
Abstract
For the microbiological safety of drinking water, disinfection methods are used to remove or inactivate microorganisms. Chlorine and chlorine dioxide are often used as disinfectants in drinking water treatment plants (DWTPs). We investigated the effectiveness of these chemicals in inactivate echovirus 30 (E30), simian 11 rotavirus (RV SA11), and human adenovirus type 2 (HAdV2) in purified water from a DWTP. Within two minutes of contact, chlorine dioxide inactivated E30 by 4-log10, RV SA11 by 3-log10, and HAdV2 could not be detected, while chlorine reduced E30 by 3-log10, RV SA11 by 2-3log10, and HAdV2 by 3-4log10. However, viral genomes could be detected for up to 2 h using qPCR. The CT method, based on a combination of disinfectant concentration and contact time, during such a short initial phase, is problematic. The high concentrations of disinfectant needed to neutralize organic matter may have a strong immediate effect on virus viability. This may lead to the underestimation of disinfection and overdosing of disinfectants in water with organic contamination. These results are useful for the selection of disinfection systems for reuse of treated wastewater and in the risk assessment of water treatment processes using chlorine and chlorine dioxide.
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Affiliation(s)
- Fredy Saguti
- Institute of Biomedicine, Department of Infectious Diseases, University of Gothenburg, 413 46 Gothenburg, Sweden
| | - Inger Kjellberg
- Göteborgs Stad Kretslopp och Vatten, 424 23 Gothenburg, Sweden
| | - Marianela Patzi Churqui
- Institute of Biomedicine, Department of Infectious Diseases, University of Gothenburg, 413 46 Gothenburg, Sweden
| | - Hao Wang
- Institute of Biomedicine, Department of Infectious Diseases, University of Gothenburg, 413 46 Gothenburg, Sweden
| | - Timur Tunovic
- Institute of Biomedicine, Department of Infectious Diseases, University of Gothenburg, 413 46 Gothenburg, Sweden
| | - Jakob Ottoson
- Department of Risk and Benefit Assessment, Swedish Food Agency, 75126 Uppsala, Sweden
| | - Olof Bergstedt
- Göteborgs Stad Kretslopp och Vatten, 424 23 Gothenburg, Sweden
| | - Helene Norder
- Institute of Biomedicine, Department of Infectious Diseases, University of Gothenburg, 413 46 Gothenburg, Sweden
| | - Kristina Nyström
- Institute of Biomedicine, Department of Infectious Diseases, University of Gothenburg, 413 46 Gothenburg, Sweden
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Kinani S, Roumiguières A, Bouchonnet S. A Critical Review on Chemical Speciation of Chlorine-Produced Oxidants (CPOs) in Seawater. Part 2: Sampling, Sample Preparation and Non-Chromatographic and Mass Spectrometric-Based Methods. Crit Rev Anal Chem 2022:1-20. [PMID: 36288103 DOI: 10.1080/10408347.2022.2135984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Chlorination of seawater forms a range of secondary oxidative species, collectively termed "chlorine-produced oxidants" (CPOs). These compounds do not have the same biocidal efficacy, the same fate and behavior in the marine environment, the same potential formation of chlorination by-products (CBPs), nor the same effects on marine organisms. Their chemical speciation is an important step toward an accurate assessment of the effectiveness of chlorination and the potential impacts of its releases, among others. The aim of this paper - which is the second of a trilogy dedicated to the chemical speciation of CPOs in seawater - is to cover all aspects related to CPOs analysis in seawater, from sampling to instrumental determination. First, it discusses the procedures involved in synthesis, storage, and standardization of analytical standards. Second, it deals with sampling and sample preparation, addressing all relevant issues related to these two key steps. Third, it provides a comprehensive and up-to-date overview of the colorimetric, titrimetric, and electrochemical methods used for CPOs determination and thoroughly discusses their advantages and limitations. Finally, this review ends with some recommendations for progress in the field of CPO analysis with the three aforementioned approaches. Chromatographic and mass spectrometric-based methods will be covered in the third and final article (Part III).
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Affiliation(s)
- Said Kinani
- Laboratoire National d'Hydraulique et Environnement (LNHE), Division Recherche et Développement, Electricité de France (EDF), Chatou Cedex, France
| | - Adrien Roumiguières
- Laboratoire National d'Hydraulique et Environnement (LNHE), Division Recherche et Développement, Electricité de France (EDF), Chatou Cedex, France
- Laboratoire de Chimie Moléculaire, CNRS, Institut polytechnique de Paris, Route de Saclay, Palaiseau, France
| | - Stéphane Bouchonnet
- Laboratoire de Chimie Moléculaire, CNRS, Institut polytechnique de Paris, Route de Saclay, Palaiseau, France
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Lanrewaju AA, Enitan-Folami AM, Sabiu S, Swalaha FM. A review on disinfection methods for inactivation of waterborne viruses. Front Microbiol 2022; 13:991856. [PMID: 36212890 PMCID: PMC9539188 DOI: 10.3389/fmicb.2022.991856] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
Water contamination is a global health problem, and the need for safe water is ever-growing due to the public health implications of unsafe water. Contaminated water could contain pathogenic bacteria, protozoa, and viruses that are implicated in several debilitating human diseases. The prevalence and survival of waterborne viruses differ from bacteria and other waterborne microorganisms. In addition, viruses are responsible for more severe waterborne diseases such as gastroenteritis, myocarditis, and encephalitis among others, hence the need for dedicated attention to viral inactivation. Disinfection is vital to water treatment because it removes pathogens, including viruses. The commonly used methods and techniques of disinfection for viral inactivation in water comprise physical disinfection such as membrane filtration, ultraviolet (UV) irradiation, and conventional chemical processes such as chlorine, monochloramine, chlorine dioxide, and ozone among others. However, the production of disinfection by-products (DBPs) that accompanies chemical methods of disinfection is an issue of great concern due to the increase in the risks of harm to humans, for example, the development of cancer of the bladder and adverse reproductive outcomes. Therefore, this review examines the conventional disinfection approaches alongside emerging disinfection technologies, such as photocatalytic disinfection, cavitation, and electrochemical disinfection. Moreover, the merits, limitations, and log reduction values (LRVs) of the different disinfection methods discussed were compared concerning virus removal efficiency. Future research needs to merge single disinfection techniques into one to achieve improved viral disinfection, and the development of medicinal plant-based materials as disinfectants due to their antimicrobial and safety benefits to avoid toxicity is also highlighted.
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Swimming Pool Regulations in the COVID-19 Era: Assessing Acceptability and Compliance in Greek Hotels in Two Consecutive Summer Touristic Periods. WATER 2022. [DOI: 10.3390/w14050796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The COVID-19 pandemic has urged many countries to issue new regulations to assure safety in pool environments. Greece enforced stricter requirements in 2020 and 2021 for hotel pools. However, even though regulations are important, they can only be effective when accepted by the pool managers and users. The aim of this study was to (a) assess the acceptability of the regulations by hotel managers; (b) assess compliance during the summer touristic periods in 2020 and 2021; and (c) identify challenges during the implementation of the regulations that need to be addressed. Several non-compliances from the regulations were identified. Continuous chlorination with an automatic chlorinator was not a regular practice and suggested water circulation rates were poorly met. The microbiological and chemical testing frequency of the pool water and keeping the number of bathers allowed per surface area in the pool were reported as the most difficult requirements to meet. Most pool managers agreed that new measures contribute to the pool users’ safety; however, they reported increased cost as the main impediment for their implementation. The modernization of regulations governing swimming pools’ function, in terms of risk assessment orientation, will contribute to the adoption of an integrated compliance strategy on emerging health issues, such as COVID-19.
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Assessment of the Impact on Human Health of the Presence of Norovirus in Bivalve Molluscs: What Data Do We Miss? Foods 2021; 10:foods10102444. [PMID: 34681492 PMCID: PMC8535557 DOI: 10.3390/foods10102444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/08/2021] [Accepted: 10/12/2021] [Indexed: 01/22/2023] Open
Abstract
In the latest One Health ECDC EFSA technical report, Norovirus in fish and fishery products have been listed as the agent/food pair causing the highest number of strong-evidence outbreaks in the EU in 2019. This review aims to identify data gaps that must be filled in order to increase knowledge on Norovirus in bivalve molluscs, perform a risk assessment and rank the key mitigation strategies for this biological hazard, which is relevant to public health. Virologic determinations are not included in any of the food safety and process hygiene microbiologic criteria reflected in the current European regulations. In addition, the Escherichia coli-based indices of acceptable faecal contamination for primary production, as well as the food safety criteria, do not appear sufficient to indicate the extent of Norovirus contamination. The qualitative risk assessment data collected in this review suggests that bivalve molluscs present a high risk to human health for Norovirus only when consumed raw or when insufficiently cooked. On the contrary, the risk can be considered negligible when they are cooked at a high temperature, while information is still scarce for non-thermal treatments.
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Zhang H, Xu X, Tan L, Liang Z, Cao R, Wan Q, Xu H, Wang J, Huang T, Wen G. The aggregation of Aspergillus spores and the impact on their inactivation by chlorine-based disinfectants. WATER RESEARCH 2021; 204:117629. [PMID: 34509870 DOI: 10.1016/j.watres.2021.117629] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/17/2021] [Accepted: 08/29/2021] [Indexed: 06/13/2023]
Abstract
The formation of fungal biofilm goes through some different states, including monodisperse state, aggregated state, germinated state, hyphal and biofilm. The aggregation of spores is a primary step of fungal biofilm development in aquatic systems. Previous studies on the inactivation of fungi were mostly performed in the monodisperse state of fungal spores and biofilm state, however, the inactivation of aggregated fungal spores is still unclear. In this study, the aggregated characteristics of fungal spores (Aspergillus fumigatus and Aspergillus flavus) at different pH values were firstly studied, and the inactivation efficiency of fungal spores at different aggregation degree by chlorine-based disinfectants was also clarified. The results showed that the aggregation degree of Aspergillus fumigatus was the highest at pH 9.0 while it was the lowest at pH 5.0. Aggregation between fungal spores was mainly mediated by occasional adhesin-adhesin interactions and electrostatic interactions. Compared with monodisperse spores, fungal spores were more resistant to chlorine-based disinfectants with the increase of spore aggregation degree. The inactivation rate constants of Aspergillus fumigatus at 30% and 63% aggregation degree were 1.5- and 4-folds lower than that of monodisperse spores, respectively. The lower proportion of membrane damage and higher intracellular reactive oxygen species level for aggregated spores than monodisperse spores was observed according to the flow cytometric results after chlorine-based disinfectants treatment. The reasons for the lower inactivation efficiency of aggregated spores are as following: the protection of outer layer spores and signals between aggregates lead to the increase of resistance for aggregated spores. This study is meaningful for the control of the fungal spores at different states in water.
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Affiliation(s)
- Huan Zhang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Xiangqian Xu
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Lili Tan
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Zhiting Liang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Ruihua Cao
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Qiqi Wan
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Huining Xu
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Jingyi Wang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Tinglin Huang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Gang Wen
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China.
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Chen L, Deng Y, Dong S, Wang H, Li P, Zhang H, Chu W. The occurrence and control of waterborne viruses in drinking water treatment: A review. CHEMOSPHERE 2021; 281:130728. [PMID: 34010719 PMCID: PMC8084847 DOI: 10.1016/j.chemosphere.2021.130728] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/21/2021] [Accepted: 04/25/2021] [Indexed: 05/04/2023]
Abstract
As the coronavirus disease 2019 continues to spread globally, its culprit, the severe acute respiratory syndrome coronavirus 2 has been brought under scrutiny. In addition to inhalation transmission, the possible fecal-oral viral transmission via water/wastewater has also been brought under the spotlight, necessitating a timely global review on the current knowledge about waterborne viruses in drinking water treatment system - the very barrier that intercepts waterborne pathogens to terminal water users. In this article we reviewed the occurrence, concentration methods, and control strategies, also, treatment performance on waterborne viruses during drinking water treatment were summarized. Additionally, we emphasized the potential of applying the quantitative microbial risk assessment to guide drinking water treatment to mitigate the viral exposure risks, especially when the unregulated novel viral pathogens are of concern. This review paves road for better control of viruses at drinking water treatment plants to protect public health.
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Affiliation(s)
- Li Chen
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China
| | - Yang Deng
- Department of Earth and Environmental Studies, Montclair State University, Montclair, NJ, USA
| | - Shengkun Dong
- Key LLaboratory of Water Cycle and Water Security in Southern China of Guangdong Higher Education Institute, School of Civil Engineering, Sun Yat-sen University, Guangdong, China
| | - Hong Wang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China
| | - Pan Li
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China
| | - Huaiyu Zhang
- Central and Southern China Institute of Municipal Engineering Design and Research, Hubei, China
| | - Wenhai Chu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China.
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Zhang M, Ghosh S, Kumar M, Santiana M, Bleck CKE, Chaimongkol N, Altan-Bonnet N, Shuai D. Emerging Pathogenic Unit of Vesicle-Cloaked Murine Norovirus Clusters is Resistant to Environmental Stresses and UV 254 Disinfection. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:6197-6205. [PMID: 33856208 DOI: 10.1021/acs.est.1c01763] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
An individual virion was long believed to act as an independent infectious unit in virology, until the recent discovery of vesicle-cloaked virus clusters which has greatly challenged this central paradigm. Vesicle-cloaked virus clusters (also known as viral vesicles) are phospholipid-bilayer encapsulated fluid sacs that contain multiple virions or multiple copies of viral genomes. Norovirus is a global leading causative agent of gastroenteritis, and the reported prevalence of vesicle-cloaked norovirus clusters in stool has raised concerns whether the current disinfection, sanitation, and hygiene practices can effectively control environmental pollution by these pathogenic units. In this study, we have demonstrated that vesicle-cloaked murine norovirus (MNV-1) clusters were highly persistent under temperature variation (i.e., freeze-thaw) and they were partially resistant to detergent decomposition. MNV-1 vesicles were 1.89-3.17-fold more infectious in vitro than their free virus counterparts. Most importantly, MNV-1 vesicles were up to 2.16-times more resistant to UV254 disinfection than free MNV-1 at a low viral load in vitro. Interestingly, with the increase of the viral load, free MNV-1 and MNV-1 vesicles showed equivalent resistance to UV254 disinfection. We show that the increased multiplicity of infection provided by vesicles is in part responsible for these attributes. Our study, for the first time, sheds light on the environmental behavior of vesicle-cloaked virus clusters as unique emerging pathogenic units. Our study highlights the need to revisit current paradigms of disinfection, sanitation, and hygiene practices for protecting public health.
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Affiliation(s)
- Mengyang Zhang
- Department of Civil and Environmental Engineering, The George Washington University, Washington, District of Columbia 20052, United States
- Laboratory of Host-Pathogen Dynamics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Sourish Ghosh
- Laboratory of Host-Pathogen Dynamics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Manish Kumar
- Laboratory of Host-Pathogen Dynamics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Marianita Santiana
- Laboratory of Host-Pathogen Dynamics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Christopher K E Bleck
- Electron Microcopy Core, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Natthawan Chaimongkol
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Nihal Altan-Bonnet
- Laboratory of Host-Pathogen Dynamics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Danmeng Shuai
- Department of Civil and Environmental Engineering, The George Washington University, Washington, District of Columbia 20052, United States
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Ge Y, Zhang X, Shu L, Yang X. Kinetics and Mechanisms of Virus Inactivation by Chlorine Dioxide in Water Treatment: A Review. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2021; 106:560-567. [PMID: 33629148 PMCID: PMC7904506 DOI: 10.1007/s00128-021-03137-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 02/01/2021] [Indexed: 05/20/2023]
Abstract
Chlorine dioxide (ClO2), an alternative disinfectant to chlorine, has been widely applied in water and wastewater disinfection. This paper aims at presenting an overview of the inactivation kinetics and mechanisms of ClO2 with viruses. The inactivation efficiencies vary greatly among different virus species. The inactivation rates for different serotypes within a family of viruses can differ by over 284%. Generally, to achieve a 4-log removal, the exposure doses, also being referred to as Ct values (mutiplying the concentration of ClO2 and contact time) vary in the range of 0.06-10 mg L-1 min. Inactivation kinetics of viruses show two phases: an initial rapid inactivation phase followed by a tailing phase. Inactivation rates of viruses increase as pH or temperature increases, but show different trends with increasing concentrations of dissolved organic matter (DOM). Both damages in viral proteins and in the 5' noncoding region within the genome contribute to virus inactivation upon ClO2 disinfection.
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Affiliation(s)
- Yuexian Ge
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Xinran Zhang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Longfei Shu
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Xin Yang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China.
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11
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Gobeil A, Maherani B, Lacroix M. Norovirus elimination on the surface of fresh foods. Crit Rev Food Sci Nutr 2020; 62:1822-1837. [DOI: 10.1080/10408398.2020.1848784] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Alexandra Gobeil
- Research Laboratories in Sciences, Applied to Food, Canadian Irradiation Centre, Nutraceuticals and Functional Foods, Laval, Québec, Canada
| | - Behnoush Maherani
- Research Laboratories in Sciences, Applied to Food, Canadian Irradiation Centre, Nutraceuticals and Functional Foods, Laval, Québec, Canada
| | - Monique Lacroix
- Research Laboratories in Sciences, Applied to Food, Canadian Irradiation Centre, Nutraceuticals and Functional Foods, Laval, Québec, Canada
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12
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Farkas K, Walker DI, Adriaenssens EM, McDonald JE, Hillary LS, Malham SK, Jones DL. Viral indicators for tracking domestic wastewater contamination in the aquatic environment. WATER RESEARCH 2020; 181:115926. [PMID: 32417460 PMCID: PMC7211501 DOI: 10.1016/j.watres.2020.115926] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 05/07/2020] [Accepted: 05/08/2020] [Indexed: 05/13/2023]
Abstract
Waterborne enteric viruses are an emerging cause of disease outbreaks and represent a major threat to global public health. Enteric viruses may originate from human wastewater and can undergo rapid transport through aquatic environments with minimal decay. Surveillance and source apportionment of enteric viruses in environmental waters is therefore essential for accurate risk management. However, individual monitoring of the >100 enteric viral strains that have been identified as aquatic contaminants is unfeasible. Instead, viral indicators are often used for quantitative assessments of wastewater contamination, viral decay and transport in water. An ideal indicator for tracking wastewater contamination should be (i) easy to detect and quantify, (ii) source-specific, (iii) resistant to wastewater treatment processes, and (iv) persistent in the aquatic environment, with similar behaviour to viral pathogens. Here, we conducted a comprehensive review of 127 peer-reviewed publications, to critically evaluate the effectiveness of several viral indicators of wastewater pollution, including common enteric viruses (mastadenoviruses, polyomaviruses, and Aichi viruses), the pepper mild mottle virus (PMMoV), and gut-associated bacteriophages (Type II/III FRNA phages and phages infecting human Bacteroides species, including crAssphage). Our analysis suggests that overall, human mastadenoviruses have the greatest potential to indicate contamination by domestic wastewater due to their easy detection, culturability, and high prevalence in wastewater and in the polluted environment. Aichi virus, crAssphage and PMMoV are also widely detected in wastewater and in the environment, and may be used as molecular markers for human-derived contamination. We conclude that viral indicators are suitable for the long-term monitoring of viral contamination in freshwater and marine environments and that these should be implemented within monitoring programmes to provide a holistic assessment of microbiological water quality and wastewater-based epidemiology, improve current risk management strategies and protect global human health.
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Affiliation(s)
- Kata Farkas
- School of Natural Sciences, Bangor University, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK; School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey, LL59 5AB, UK.
| | - David I Walker
- Centre for Environment, Fisheries and Aquaculture Science, Weymouth, Dorset, DT4 8UB, UK
| | | | - James E McDonald
- School of Natural Sciences, Bangor University, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK
| | - Luke S Hillary
- School of Natural Sciences, Bangor University, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK
| | - Shelagh K Malham
- School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey, LL59 5AB, UK
| | - Davey L Jones
- School of Natural Sciences, Bangor University, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK; UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA, 6009, Australia
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13
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Preliminary Data Related to the Effect of Climacostol Produced by the Freshwater Ciliate Climacostomum virens on Human Adenovirus. Viruses 2020; 12:v12060658. [PMID: 32570859 PMCID: PMC7354546 DOI: 10.3390/v12060658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 01/01/2023] Open
Abstract
The new epidemiological scenario has so far focused on the environmental circulation of human viral pathogens. Owing to the side effects of chemical disinfectants, there is an increasing need for knowledge on the use of virucidal compounds, especially those of a natural origin. Climacostol is a molecule produced by a freshwater ciliate and it exhibits activity against bacterial and fungal pathogens. We thus also speculated that there might be an effect on viral viability, which has never been tested. To evaluate such activity, we chose human adenovirus (HAdV), which is representative of waterborne viruses. We conducted experiments using HAdV serotype 5, whose titer was determined by infecting HeLa cell cultures. HAdV5 was shown to be sensitive to climacostol at a concentration of 0.0002 mg/mL, with an approximate 3 Log10 reduction when the initial titer of HAdV5 was approximately 104 and 103 TCID50/mL. These preliminary results could be an important starting point for further research aimed at improving the characterization of climacostol activity under different experimental conditions and against various viruses, including enveloped ones (i.e., the coronavirus). The production of climacostol by a protist living in fresh water also suggests a possible application in the activated sludge of wastewater treatment plants.
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14
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Waldman P, Lucas FS, Varrault G, Moulin L, Wurtzer S. Hydrophobic Organic Matter Promotes Coxsackievirus B5 Stabilization and Protection from Heat. FOOD AND ENVIRONMENTAL VIROLOGY 2020; 12:118-129. [PMID: 31912415 DOI: 10.1007/s12560-019-09418-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 12/30/2019] [Indexed: 05/28/2023]
Abstract
In urban rivers, many of which are used for drinking water production, viruses encounter a range of particulate, colloidal, and dissolved organic and inorganic compounds. To date, the impact of environmental organic matter on virus persistence in the environment has received little attention. In the present study, fresh water was fractioned to separate particulate natural organic matter from dissolved forms. Each fraction was tested for its ability to promote coxsackievirus B5 resistance to heat inactivation. Our results demonstrate that, at natural concentrations, environmental waters contain particulate or dissolved compounds that are able to protect viruses from heat. We also show that hydrophobic compounds promote an efficient protection against heat inactivation. This study suggests that local conditions encountered by viruses in the environment could greatly impact their persistence.
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Affiliation(s)
- P Waldman
- Laboratoire Eau Environnement Et Systèmes Urbains (LEESU, UMR MA 102), Faculté des Sciences Et Technologie, Université Paris-Est, 61 Avenue du Général de Gaulle, 94000, Créteil, France
| | - F S Lucas
- Laboratoire Eau Environnement Et Systèmes Urbains (LEESU, UMR MA 102), Faculté des Sciences Et Technologie, Université Paris-Est, 61 Avenue du Général de Gaulle, 94000, Créteil, France
| | - G Varrault
- Laboratoire Eau Environnement Et Systèmes Urbains (LEESU, UMR MA 102), Faculté des Sciences Et Technologie, Université Paris-Est, 61 Avenue du Général de Gaulle, 94000, Créteil, France
| | - L Moulin
- Eau de Paris, DRDQE, 33 Avenue Jean Jaurès, 94200, Ivry sur Seine, France.
| | - S Wurtzer
- Eau de Paris, DRDQE, 33 Avenue Jean Jaurès, 94200, Ivry sur Seine, France
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15
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Environmental and Adaptive Changes Necessitate a Paradigm Shift for Indicators of Fecal Contamination. Microbiol Spectr 2020. [DOI: 10.1128/microbiolspec.erv-0001-2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
ABSTRACT
Changes in the occurrence, distribution, and seasonal variation of waterborne pathogens due to global climate change may increase the risk of human exposure to these microorganisms, thus heightening the need for more reliable surveillance systems. Routine monitoring of drinking water supplies and recreational waters is performed using fecal indicator microorganisms, such as
Escherichia coli
,
Enterococcus
spp., and coliphages. However, the presence and numbers of these indicators, especially
E. coli
and
Enterococcus
spp., do not correlate well with those of other pathogens, especially enteric viruses, which are a major cause of waterborne outbreaks associated with contaminated water and food, and recreational use of lakes, ponds, rivers, and estuarine waters. For that reason, there is a growing need for a surveillance system that can detect and quantify viral pathogens directly in water sources to reduce transmission of pathogens associated with fecal transmission. In this review, we present an updated overview of relevant waterborne enteric viruses that we believe should be more commonly screened to better evaluate water quality and to determine the safety of water use and reuse and of epidemiological data on viral outbreaks. We also discuss current methodologies that are available to detect and quantify these viruses in water resources. Finally, we highlight challenges associated with virus monitoring. The information presented in this review is intended to aid in the assessment of human health risks due to contact with water sources, especially since current environmental and adaptive changes may be creating the need for a paradigm shift for indicators of fecal contamination.
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16
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Rachmadi AT, Kitajima M, Kato T, Kato H, Okabe S, Sano D. Required Chlorination Doses to Fulfill the Credit Value for Disinfection of Enteric Viruses in Water: A Critical Review. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:2068-2077. [PMID: 31927958 DOI: 10.1021/acs.est.9b01685] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A credit value of virus inactivation has been assigned to the disinfection step in international and domestic guidelines for wastewater reclamation and reuse. To fulfill the credit value for water disinfection, water engineers need to apply an appropriate disinfection strength, expressed as a CT value (mg × min/L), which is a product of disinfectant concentration and contact time, against enteric viruses in wastewater. In the present study, we extracted published experimental data on enteric virus inactivation using free chlorine and monochloramine and applied the Tobit analysis and simple linear regression analysis to calculate the range of CT values (mg × min/L) needed for 4-log10 inactivation. Data were selected from peer-reviewed papers containing kinetics data of virus infectivity and chlorine residual in water. Coxsackie B virus and echovirus require higher CT values (lower susceptibility) for 4-log10 inactivation than adenovirus and a human norovirus surrogate (murine norovirus) with free chlorine. On the other hand, adenovirus has lower susceptibility to monochloramine compared to murine norovirus, coxsackievirus, and echovirus. The factors that influence the required CT value are virus type, pH, water temperature, and water matrix. This systematic review demonstrates that enteroviruses and adenovirus are appropriate representative enteric viruses to evaluate water disinfection using free chlorine and monochloramine, respectively.
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Affiliation(s)
- Andri Taruna Rachmadi
- Department of Frontier Science for Advanced Environment, Graduate School of Environmental Studies , Tohoku University , Aoba 6-6-06, Aramaki, Aoba-ku , Sendai , Miyagi 980-8579 , Japan
- Division of Environmental Engineering , Hokkaido University , North 13, West 8, Kita-ku , Sapporo , Hokkaido 060-8628 , Japan
- Water Desalination and Reuse Center (WDRC) , King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
| | - Masaaki Kitajima
- Division of Environmental Engineering , Hokkaido University , North 13, West 8, Kita-ku , Sapporo , Hokkaido 060-8628 , Japan
| | - Tsuyoshi Kato
- Division of Electronics and Informatics, Faculty of Science and Technology , Gunma University , Tenjin-cho 1-5-1 , Kiryu , Gunma 376-8515 , Japan
- Center for Research on Adoption of NextGen Transportation Systems (CRANTS) , Gunma University , Aramaki-machi 4-2 , Maebashi , Gunma 371-8510 , Japan
- Integrated Institute for Regulatory Science , Waseda University , Tsurumaki-cho 513, Shinjuku-ku , Tokyo 162-0041 , Japan
| | - Hiroyuki Kato
- Japan Institute of Wastewater Engineering and Technology , 3-1 Suido-Cho, Shinjuku-ku , Tokyo 162-0811 , Japan
- New Industry Creation Hatchery Center , Tohoku University , Aoba 6-6-10, Aramaki, Aoba-ku , Sendai , Miyagi 980-8579 , Japan
| | - Satoshi Okabe
- Division of Environmental Engineering , Hokkaido University , North 13, West 8, Kita-ku , Sapporo , Hokkaido 060-8628 , Japan
| | - Daisuke Sano
- Department of Frontier Science for Advanced Environment, Graduate School of Environmental Studies , Tohoku University , Aoba 6-6-06, Aramaki, Aoba-ku , Sendai , Miyagi 980-8579 , Japan
- Department of Civil and Environmental Engineering , Tohoku University , Aoba 6-6-06, Aramaki, Aoba-ku , Sendai , Miyagi 980-8579 , Japan
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17
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Silverman AI, Boehm AB. Systematic Review and Meta-Analysis of the Persistence and Disinfection of Human Coronaviruses and Their Viral Surrogates in Water and Wastewater. ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 2020; 7:544-553. [PMID: 37566367 PMCID: PMC7294895 DOI: 10.1021/acs.estlett.0c00313] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/28/2020] [Accepted: 05/28/2020] [Indexed: 05/18/2023]
Abstract
A systematic review and meta-analysis was conducted to identify decay rate constants (k) of human coronaviruses and their viral surrogates (i.e., animal coronaviruses and the enveloped bacteriophage Phi6) in water and wastewater and disinfection rates with exposure to free chlorine and germicidal ultraviolet light (UV254). Here, 73 k were identified, with only 12 for human coronaviruses, as opposed to animal coronaviruses or Phi6. In the absence of disinfectants, k increased with temperature. Between 22 and 25 °C, mean k for coronaviruses ranged from 0.19 ± 0.06 d-1 in laboratory buffer (n = 4) to 2.9 ± 0.03 d-1 in sterilized wastewater (n = 3), which are within the ranges observed for Phi6 and nonenveloped viruses. No free chlorine or UV254 disinfection studies for coronaviruses were identified that met the systematic review inclusion criteria, although evidence from the literature suggests that coronaviruses would be inactivated if disinfectant doses recommended for nonenveloped viruses were applied. Three disinfection experiments were identified for Phi6. However, given different genome compositions and virion structures between coronaviruses and Phi6, it is not clear whether Phi6 should be used as a surrogate for evaluating free chlorine or UV254k. Therefore, there is a critical need for additional studies that specifically evaluate disinfection kinetics of coronaviruses in the aqueous environment.
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Affiliation(s)
- Andrea I. Silverman
- Department of Civil and Urban Engineering,
New York University Tandon School of Engineering, 6 Metrotech
Center, Brooklyn, New York 11201, United States
- Department of Global Health, New York
University School of Global Public Health, New York, New York 10012,
United States
| | - Alexandria B. Boehm
- Department of Civil and Environmental Engineering,
Stanford University, Stanford, California 94305,
United States
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18
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Abstract
Insufficient funding and operator training, logistics of chemical transport, and variable source water quality can pose challenges for small drinking water treatment systems. Portable, robust electrochemical processes may offer a strategy to address these challenges. In this study, electrocoagulation (EC) and electrooxidation (EO) were investigated using two model surface waters and two model groundwaters to determine the efficacy of sequential EC-EO for mitigating Escherichia coli. EO alone (1.67 mA/cm2, 1 min) provided 0.03 to 3.9 logs mitigation in the four model waters. EC alone (10 mA/cm2, 5 min) achieved ≥1 log E. coli mitigation in all model waters. Sequential EC-EO did not achieve greater mitigation than EC alone. To enhance removal of natural organic matter, the initial pH was decreased. Lower initial pH (pH 5–6) improved E. coli mitigation during both stages of EC-EO. EC-EO also had slightly greater E. coli mitigation than EC alone at lower pH. However, EO alone provided more energy efficient E. coli mitigation than either EC or EC-EO.
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19
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Predictive Water Virology: Hierarchical Bayesian Modeling for Estimating Virus Inactivation Curve. WATER 2019. [DOI: 10.3390/w11102187] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Hazard analysis and critical control point (HACCP) are a series of actions to be taken to ensure product consumption safety. In food poisoning risk management, researchers in the field of predictive microbiology calculate the values that provide minimum stress (e.g., temperature and contact time in heating) for sufficient microbe inactivation based on mathematical models. HACCP has also been employed for health risk management in sanitation safety planning (SSP), but the application of predictive microbiology to water-related pathogens is difficult because the variety of pathogen types and the complex composition of the wastewater matrix does not allow us to make a simple mathematical model to predict inactivation efficiency. In this study, we performed a systematic review and meta-analysis to construct predictive inactivation curves using free chlorine for enteric viruses based on a hierarchical Bayesian model using parameters such as water quality. Our model considered uncertainty among virus disinfection tests and difference in genotype-dependent sensitivity of a virus to disinfectant. The proposed model makes it possible to identify critical disinfection stress capable of reducing virus concentration that is below the tolerable concentration to ensure human health.
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20
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Nilsen V, Christensen E, Myrmel M, Heistad A. Spatio-temporal dynamics of virus and bacteria removal in dual-media contact-filtration for drinking water. WATER RESEARCH 2019; 156:9-22. [PMID: 30897546 DOI: 10.1016/j.watres.2019.02.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 02/08/2019] [Accepted: 02/13/2019] [Indexed: 05/24/2023]
Abstract
Microorganism removal efficiencies in deep bed filters vary with time and depth in the filter bed as the filter collects particles. Improved knowledge of such dynamics is relevant for the design, operation and microbial risk assessment of filtration processes for drinking water treatment. Here we report on a high-resolution spatio-temporal characterization of virus and bacteria removal in a pilot-scale dual-media filter, operated in contact-filtration mode. Microorganisms investigated were bacteriophage Salmonella typhimurium 28B (plaque assay, n=154)), fRNA phage MS2 (plaque assay/RT-qPCR, n=87) and E. coli (Colilert-18, n=73). Microscopic and macroscopic filtration models were used to investigate and characterize the removal dynamics. Results show that ripening/breakthrough fronts for turbidity, viruses and E. coli migrated in a wave-like manner across the depth of the filter. Virus removal improved continuously throughout the filter cycle and viruses broke through almost simultaneously with turbidity. Ripening for E. coli took longer than ripening for turbidity, but the bacteria broke through before turbidity breakthrough. Instantaneous log-removal peaked at 3.2, 3.0 and 4.5 for 28B, MS2 and E. coli, respectively. However, true average log-removal during the period of stable effluent turbidity was significantly lower at 2.5, 2.3 and 3.6, respectively. Peak observed filter coefficients λ were higher than predicted by ideal filtration theory. This study demonstrates the importance of carefully designed sampling regimes when characterizing microorganism removal efficiencies of deep bed filters.
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Affiliation(s)
- Vegard Nilsen
- Norwegian University of Life Sciences, Faculty of Science and Technology, P.O.Box 5003, N-1432, Ås, Norway.
| | - Ekaterina Christensen
- Norwegian University of Life Sciences, Faculty of Veterinary Medicine, P.O.Box 8146 Dep, N-0033, Oslo, Norway
| | - Mette Myrmel
- Norwegian University of Life Sciences, Faculty of Veterinary Medicine, P.O.Box 8146 Dep, N-0033, Oslo, Norway
| | - Arve Heistad
- Norwegian University of Life Sciences, Faculty of Science and Technology, P.O.Box 5003, N-1432, Ås, Norway
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21
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Sommer J, Trautner C, Witte AK, Fister S, Schoder D, Rossmanith P, Mester PJ. Don't Shut the Stable Door after the Phage Has Bolted-The Importance of Bacteriophage Inactivation in Food Environments. Viruses 2019; 11:E468. [PMID: 31121941 PMCID: PMC6563225 DOI: 10.3390/v11050468] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/05/2019] [Accepted: 05/17/2019] [Indexed: 12/11/2022] Open
Abstract
In recent years, a new potential measure against foodborne pathogenic bacteria was rediscovered-bacteriophages. However, despite all their advantages, in connection to their widespread application in the food industry, negative consequences such as an uncontrolled phage spread as well as a development of phage resistant bacteria can occur. These problems are mostly a result of long-term persistence of phages in the food production environment. As this topic has been neglected so far, this article reviews the current knowledge regarding the effectiveness of disinfectant strategies for phage inactivation and removal. For this purpose, the main commercial phage products, as well as their application fields are first discussed in terms of applicable inactivation strategies and legal regulations. Secondly, an overview of the effectiveness of disinfectants for bacteriophage inactivation in general and commercial phages in particular is given. Finally, this review outlines a possible strategy for users of commercial phage products in order to improve the effectiveness of phage inactivation and removal after application.
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Affiliation(s)
- Julia Sommer
- Christian Doppler Laboratory for Monitoring of Microbial Contaminants, Department for Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria.
| | - Christoph Trautner
- Christian Doppler Laboratory for Monitoring of Microbial Contaminants, Department for Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria.
| | - Anna Kristina Witte
- Christian Doppler Laboratory for Monitoring of Microbial Contaminants, Department for Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria.
- HTK Hygiene Technologie Kompetenzzentrum GmbH, Buger Str. 80, 96049 Bamberg, Germany.
| | - Susanne Fister
- Former member of Christian Doppler Laboratory for Monitoring of Microbial Contaminants, Institute of Milk Hygiene, Milk Technology and Food Science, Department for Farm Animal and Public Veterinary Health, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria.
| | - Dagmar Schoder
- Unit of Food Microbiology, Institute of Food Safety, Food Technology and Veterinary Public Health, Department for Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria.
| | - Peter Rossmanith
- Christian Doppler Laboratory for Monitoring of Microbial Contaminants, Department for Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria.
- Unit of Food Microbiology, Institute of Food Safety, Food Technology and Veterinary Public Health, Department for Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria.
| | - Patrick-Julian Mester
- Christian Doppler Laboratory for Monitoring of Microbial Contaminants, Department for Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria.
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22
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Efficacy of Flushing and Chlorination in Removing Microorganisms from a Pilot Drinking Water Distribution System. WATER 2019. [DOI: 10.3390/w11050903] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
To ensure delivery of microbiologically safe drinking water, the physical integrity of the distribution system is an important control measure. During repair works or an incident the drinking water pipe is open and microbiologically contaminated water or soil may enter. Before taking the pipe back into service it must be cleaned. The efficacy of flushing and shock chlorination was tested using a model pipe-loop system with a natural or cultured biofilm to which a microbial contamination (Escherichia coli, Clostridium perfringens spores and phiX174) was added. On average, flushing removed 1.5–2.7 log microorganisms from the water, but not the biofilm. In addition, sand added to the system was not completely removed. Flushing velocity (0.3 or 1.5 m/s) did not affect the efficacy. Shock chlorination (10 mg/L, 1–24 h) was very effective against E. coli and phiX174, but C. perfringens spores were partly resistant. Chlorination was slightly more effective in pipes with a natural compared to a cultured biofilm. Flushing alone is thus not sufficient after high risk repair works or incidents, and shock chlorination should be considered to remove microorganisms to ensure microbiologically safe drinking water. Prevention via hygienic working procedures, localizing and isolating the contamination source and issuing boil water advisories remain important, especially during confirmed contamination events.
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23
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Wati S, Robinson BS, Mieog J, Blackbeard J, Keegan AR. Chlorine inactivation of coxsackievirus B5 in recycled water destined for non-potable reuse. JOURNAL OF WATER AND HEALTH 2019; 17:124-136. [PMID: 30758309 DOI: 10.2166/wh.2018.393] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Currently guidelines for disinfection of water with free chlorine, while primarily developed for potable water, are often used for virus disinfection of nitrified recycled water of >1 NTU (Nephelometric Turbidity Unit). More information is needed on the disinfection efficacy of free chlorine for viruses in waters of varying turbidity and pH due to significant reuse of treated wastewater of varying quality. In this study, disinfection efficacy in nitrified/denitrified activated sludge treated wastewater was investigated for coxsackievirus B5 (CB5), an enterovirus known to be highly resistant to free chlorine. The required chlorine contact times (CT) values (mg.min/L) for inactivation of CB5 were established in treated wastewater at 10 °C and of varying turbidity (0.2, 2, 5 and 20 NTU) and pH (7, 8 and 9). CTs were calculated to achieve 1 to 4 log10 inactivation. Robust data is presented in support of the chlorine CT values required to inactivate a chlorine-resistant virus in a range of turbidities and pHs in treated wastewaters. The testing method used a conservative approach and the data presented have been used to develop the free chlorine virus inactivation guildelines for recycled water in Victoria and South Australia, Australia.
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Affiliation(s)
- Satiya Wati
- SA Water, 250 Victoria Square, Adelaide, SA 5000, Australia E-mail:
| | - Bret S Robinson
- SA Water, 250 Victoria Square, Adelaide, SA 5000, Australia E-mail:
| | - John Mieog
- Melbourne Water, 990 La Trobe Street, Docklands, VIC 3001, Australia
| | - Judy Blackbeard
- Melbourne Water, 990 La Trobe Street, Docklands, VIC 3001, Australia
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24
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Paranthaman K, Pringle E, Burgess A, Macdonald N, Sedgwick J. An unusual outbreak of norovirus associated with a Halloween-themed swimming pool party in England, 2016. Euro Surveill 2018; 23. [PMID: 30401012 PMCID: PMC6337073 DOI: 10.2807/1560-7917.es.2018.23.44.1700773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In October 2016, an outbreak of norovirus occurred among attendees of a Halloween-themed party at a public swimming pool in the south-east of England. Norovirus genogroup II was confirmed in 11 cases. In the retrospective cohort study of pool users, 68 individuals (37 female and 31 male), with a median age of 11 years (range: 0–50 years), met the case definition of developing diarrhoea or vomiting between 6 and 72 h after the pool visit. Multivariable analysis showed that increasing age was associated with a reduced risk of illness (odds ratio = 0.91; 95% confidence interval: 0.83–0.99). Pool behaviours (swallowing water) and the timing of visit (attending pool party after automatic dosing system was switched off) were independently associated with increased risk. Environmental investigations revealed that the automatic dosing system was switched off to reduce chlorine levels to an intended range of 0.5–1 parts per million to facilitate the use of a commercial red dye. There was a lack of compliance with the operator's own pool operating procedures, particularly on maintaining effective chlorine levels in pool water, recording of test results and recording of actions undertaken. This outbreak highlights the risks of lowering chlorine levels when using pool water colourants.
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Affiliation(s)
- Karthik Paranthaman
- Public Health England, National Infections Service, Field Service, London, United Kingdom
- Public Health England South East, Ashford, United Kingdom
| | - Ellen Pringle
- Public Health England, National Infections Service, Field Service, London, United Kingdom
| | - Alison Burgess
- Public Health England South East, Ashford, United Kingdom
| | - Neil Macdonald
- Public Health England, National Infections Service, Field Service, London, United Kingdom
| | - James Sedgwick
- Public Health England, National Infections Service, Field Service, London, United Kingdom
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25
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Li GQ, Huo ZY, Wu QY, Lu Y, Hu HY. Synergistic effect of combined UV-LED and chlorine treatment on Bacillus subtilis spore inactivation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 639:1233-1240. [PMID: 29929290 DOI: 10.1016/j.scitotenv.2018.05.240] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 05/19/2018] [Accepted: 05/19/2018] [Indexed: 06/08/2023]
Abstract
An ultraviolet (UV)-based advanced oxidation process (AOP) for disinfecting water is introduced in this paper. This study aimed to evaluate the potential of UV light-emitting diodes (UV-LEDs)/chlorine AOP (UV/Cl2) for Bacillus subtilis spore inactivation. Chlorine was combined with 265 and 280 nm LEDs (UV265/Cl2, UV280/Cl2) and investigated. The addition of 4.0 mg/L of free chlorine at pH 7.0 in the presence of 125 mJ/cm2 of UV irradiation resulted in an additional 1.8-log reduction in UV265/Cl2 and 1.5-log reduction in UV280/Cl2. There was no observed enhancement in spore inactivation with the addition of a radical scavenger, t-BuOH, which indicated the role of •OH in the synergistic effect. To quantitatively evaluate the synergism, the primary treatment with UV/Cl2 was followed by further UV or Cl2 treatment. After UV/Cl2 pretreatment at different pH levels, the 265 and 280 nm LEDs treatment enhanced an approximate 0.4-0.5-log reduction compared to UV only, and Cl2 treatment enhanced an approximate 0.7-1.1-log reduction compared to Cl2 only. In addition, at pH 7.0, in UV265/Cl2-Cl2 and UV280/Cl2-Cl2, the inactivation rate constant k increased by approximately 2 and 1.5 times, respectively. The CT for the lag phases (CTlag) reduced to approximately 67 and 58%, respectively. Similar results were obtained at pH 7.5 and 8.0, and in the secondary effluent. The synergistic effect on spore inactivation suggested that the pathogen inactivation efficiency of sequential UV and chlorine disinfection processes, which are commonly applied, can be significantly enhanced by adding chlorine prior to UV treatment.
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Affiliation(s)
- Guo-Qiang Li
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Zheng-Yang Huo
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Qian-Yuan Wu
- Shenzhen Laboratory of Microorganism Application and Risk Control, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, PR China
| | - Yun Lu
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China.
| | - Hong-Ying Hu
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China; Shenzhen Environmental Science and New Energy Technology Engineering Laboratory, Tsinghua-Berkeley Shenzhen Institute, Shenzhen 518055, PR China.
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Dunkin N, Weng S, Coulter CG, Jacangelo JG, Schwab KJ. Impacts of virus processing on human norovirus GI and GII persistence during disinfection of municipal secondary wastewater effluent. WATER RESEARCH 2018; 134:1-12. [PMID: 29407643 DOI: 10.1016/j.watres.2018.01.053] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 01/20/2018] [Accepted: 01/22/2018] [Indexed: 05/03/2023]
Abstract
Noroviruses cause significant global health burdens and waterborne transmission is a known exposure pathway. Chlorination is the most common method of disinfection for water and wastewater worldwide. The purpose of this study was to investigate the underlying causes for discrepancies in human norovirus (hNoV) resistance to free chlorine that have been previously published, and to assess hNoV GI and GII persistence during disinfection of municipal secondary wastewater (WW) effluent. Our results reveal that choice of hNoV purification methodology prior to seeding the viruses in an experimental water matrix influences disinfection outcomes in treatment studies. Common hNoV purification processes such as solvent extraction and 0.45-μm filtration were ineffective in removing high levels of organics introduced into water or wastewater samples when seeding norovirus positive stool. These methods resulted in experimental water matrices receiving an additional 190 mg/L as Cl2 of 15-s chlorine demand and approximately 440 mg/L as Cl2 of 30-min chlorine demand due to seeding norovirus positive stool at 1% w/v. These high organic loads impact experimental water chemistry and bias estimations of hNoV persistence. Advanced purification of norovirus positive stool using sucrose cushion ultracentrifugation and ultrafiltration reduced 15-s chlorine demands by 99% and TOC by 93% for loose (i.e. unformed diarrhea) stools. Using these methods, hNoV GI and GII persistence was investigated during free chlorination of municipal WW. A suite five of kinetic inactivation models was fit to viral reverse transcription-qPCR reduction data, and model predicted CT values for 1, 2, and 3 log10 reduction of hNoV GI in municipal WW by free chlorine were 0.3, 2.1, and 7.8 mg-min/L, respectively. Model predicted CT values for reduction of hNoV GII in WW were 0.4, 2.0, and 7.0 mg-min/L, respectively. These results indicate that current WW treatment plant disinfection practices employing free chlorine are likely protective for public health with regards to noroviruses, and will achieve at least 3-log reduction of hNoV GI and GII RNA despite previous reports of high hNoV resistance.
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Affiliation(s)
- Nathan Dunkin
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - ShihChi Weng
- JHU/MWH Alliance, Johns Hopkins University, Baltimore, MD, USA
| | - Caroline G Coulter
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Joseph G Jacangelo
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA; JHU/MWH Alliance, Johns Hopkins University, Baltimore, MD, USA; MWH-Stantec, Pasadena, CA, USA
| | - Kellogg J Schwab
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA; JHU/MWH Alliance, Johns Hopkins University, Baltimore, MD, USA.
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Dunkin N, Weng S, Jacangelo JG, Schwab KJ. Inactivation of Human Norovirus Genogroups I and II and Surrogates by Free Chlorine in Postharvest Leafy Green Wash Water. Appl Environ Microbiol 2017; 83:e01457-17. [PMID: 28887415 PMCID: PMC5666131 DOI: 10.1128/aem.01457-17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 09/06/2017] [Indexed: 11/20/2022] Open
Abstract
Human noroviruses (hNoVs) are a known public health concern associated with the consumption of leafy green vegetables. While a number of studies have investigated pathogen reduction on the surfaces of leafy greens during the postharvest washing process, there remains a paucity of data on the level of treatment needed to inactivate viruses in the wash water, which is critical for preventing cross-contamination. The objective of this study was to quantify the susceptibility of hNoV genotype I (GI), hNoV GII, murine norovirus (MNV), and bacteriophage MS2 to free chlorine in whole leaf, chopped romaine, and shredded iceberg lettuce industrial leafy green wash waters, each sampled three times over a 4-month period. A suite of kinetic inactivation models was fit to the viral reduction data to aid in quantification of concentration-time (CT) values. Results indicate that 3-log10 infectivity reduction was achieved at CT values of less than 0.2 mg · min/liter for MNV and 2.5 mg · min/liter for MS2 in all wash water types. CT values for 2-log10 molecular reduction of hNoV GI in whole leaf and chopped romaine wash waters were 1.5 and 0.9 mg · min/liter, respectively. For hNoV GII, CT values were 13.0 and 7.5 mg · min/liter, respectively. In shredded iceberg wash water, 3-log10 molecular reduction was not observed for any virus over the time course of experiments. These findings demonstrate that noroviruses may exhibit genogroup-dependent resistance to free chlorine and emphasize the importance of distinguishing between genogroups in hNoV persistence studies.IMPORTANCE Postharvest washing of millions of pounds of leafy greens is performed daily in industrial processing facilities with the intention of removing dirt, debris, and pathogenic microorganisms prior to packaging. Modest inactivation of pathogenic microorganisms (less than 2 log10) is known to occur on the surfaces of leafy greens during washing. Therefore, the primary purpose of the sanitizing agent is to maintain microbial quality of postharvest processing water in order to limit cross-contamination. This study modeled viral inactivation data and quantified the free-chlorine CT values that processing facilities must meet in order to achieve the desired level of hNoV GI and GII reduction. Disinfection experiments were conducted in industrial leafy green wash water collected from a full-scale fresh produce processing facility in the United States, and hNoV GI and GII results were compared with surrogate molecular and infectivity data.
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Affiliation(s)
- Nathan Dunkin
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - ShihChi Weng
- JHU/MWH-Stantec Alliance, Johns Hopkins University, Baltimore, Maryland, USA
| | - Joseph G Jacangelo
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
- JHU/MWH-Stantec Alliance, Johns Hopkins University, Baltimore, Maryland, USA
- MWH-Stantec, Pasadena, California, USA
| | - Kellogg J Schwab
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
- JHU/MWH-Stantec Alliance, Johns Hopkins University, Baltimore, Maryland, USA
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Dunkin N, Weng S, Coulter CG, Jacangelo JG, Schwab KJ. Reduction of Human Norovirus GI, GII, and Surrogates by Peracetic Acid and Monochloramine in Municipal Secondary Wastewater Effluent. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:11918-11927. [PMID: 28910089 DOI: 10.1021/acs.est.7b02954] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The objective of this study was to characterize human norovirus (hNoV) GI and GII reductions during disinfection by peracetic acid (PAA) and monochloramine in secondary wastewater (WW) and phosphate buffer (PB) as assessed by reverse transcription-qPCR (RT-qPCR). Infectivity and RT-qPCR reductions are also presented for surrogate viruses murine norovirus (MNV) and bacteriophage MS2 under identical experimental conditions to aid in interpretation of hNoV molecular data. In WW, RT-qPCR reductions were less than 0.5 log10 for all viruses at concentration-time (CT) values up to 450 mg-min/L except for hNoV GI, where 1 log10 reduction was observed at CT values of less than 50 mg-min/L for monochloramine and 200 mg-min/L for PAA. In PB, hNoV GI and MNV exhibited comparable resistance to PAA and monochloramine with CT values for 2 log10 RT-qPCR reduction between 300 and 360 mg-min/L. Less than 1 log10 reduction was observed for MS2 and hNoV GII in PB at CT values for both disinfectants up to 450 mg-min/L. Our results indicate that hNoVs exhibit genogroup dependent resistance and that disinfection practices targeting hNoV GII will result in equivalent or greater reductions for hNoV GI. These data provide valuable comparisons between hNoV and surrogate molecular signals that can begin the process of informing regulators and engineers on WW treatment plant design and operational practices necessary to inactivate hNoVs.
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Affiliation(s)
- Nathan Dunkin
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University , Baltimore, Maryland 21205, United States
| | - ShihChi Weng
- JHU/MWH-Stantec Alliance, Johns Hopkins University, Baltimore, Maryland 21205, United States
| | - Caroline G Coulter
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University , Baltimore, Maryland 21205, United States
| | - Joseph G Jacangelo
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University , Baltimore, Maryland 21205, United States
- JHU/MWH-Stantec Alliance, Johns Hopkins University, Baltimore, Maryland 21205, United States
- MWH-Stantec , Pasadena, California 91101, United States
| | - Kellogg J Schwab
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University , Baltimore, Maryland 21205, United States
- JHU/MWH-Stantec Alliance, Johns Hopkins University, Baltimore, Maryland 21205, United States
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Ma X, Bibby K. Free chlorine and monochloramine inactivation kinetics of Aspergillus and Penicillium in drinking water. WATER RESEARCH 2017; 120:265-271. [PMID: 28501787 DOI: 10.1016/j.watres.2017.04.064] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Revised: 04/17/2017] [Accepted: 04/26/2017] [Indexed: 06/07/2023]
Abstract
Fungi are near-ubiquitous in potable water distribution systems, but the disinfection kinetics of commonly identified fungi are poorly studied. In the present study, laboratory scale experiments were conducted to evaluate the inactivation kinetics of Aspergillus fumigatus, Aspergillus versicolor, and Penicillium purpurogenum by free chlorine and monochloramine. The observed inactivation data were then fit to a delayed Chick-Watson model. Based on the model parameter estimation, the Ct values (integrated product of disinfectant concentration C and contact time t over defined time intervals) for 99.9% inactivation of the tested fungal strains ranged from 48.99 mg min/L to 194.7 mg min/L for free chlorine and from 90.33 mg min/L to 531.3 mg min/L for monochloramine. Fungal isolates from a drinking water system (Aspergillus versicolor and Penicillium purpurogenum) were more disinfection resistant than Aspergillus fumigatus type and clinical isolates. The required 99.9% inactivation Ct values for the tested fungal strains are higher than E. coli, a commonly monitored indicator bacteria, and within a similar range for bacteria commonly identified within water distribution systems, such as Mycobacterium spp. and Legionella spp.
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Affiliation(s)
- Xiao Ma
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Kyle Bibby
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA; Department of Computational and Systems Biology, University of Pittsburgh Medical School, Pittsburgh, PA 15261, USA.
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30
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Gerba CP, Betancourt WQ. Viral Aggregation: Impact on Virus Behavior in the Environment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:7318-7325. [PMID: 28599109 DOI: 10.1021/acs.est.6b05835] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Aggregates of viruses can have a significant impact on quantification and behavior of viruses in the environment. Viral aggregates may be formed in numerous ways. Viruses may form crystal like structures and aggregates in the host cell during replication or may form due to changes in environmental conditions after virus particles are released from the host cells. Aggregates tend to form near the isoelectric point of the virus, under the influence of certain salts and salt concentrations in solution, cationic polymers, and suspended organic matter. The given conditions under which aggregates form in the environment are highly dependent on the type of virus, type of salts in solution (cation, anion. monovalent, divalent) and pH. However, virus type greatly influences the conditions when aggregation/disaggregation will occur, making predictions difficult under any given set of water quality conditions. Most studies have shown that viral aggregates increase the survival of viruses in the environment and resistance to disinfectants, especially with more reactive disinfectants. The presence of viral aggregates may also result in overestimation of removal by filtration processes. Virus aggregation-disaggregation is a complex process and predicting the behavior of any individual virus is difficult under a given set of environmental circumstances without actual experimental data.
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Affiliation(s)
- Charles P Gerba
- Department of Soil, Water and Environmental Science Water & Energy Sustainable Technology (WEST) Center, The University of Arizona , 2959 W. Calle Agua, Nueva Tucson, Arizona 85745, United States
| | - Walter Q Betancourt
- Department of Soil, Water and Environmental Science Water & Energy Sustainable Technology (WEST) Center, The University of Arizona , 2959 W. Calle Agua, Nueva Tucson, Arizona 85745, United States
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Dunkin N, Weng S, Schwab KJ, McQuarrie J, Bell K, Jacangelo JG. Comparative Inactivation of Murine Norovirus and MS2 Bacteriophage by Peracetic Acid and Monochloramine in Municipal Secondary Wastewater Effluent. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:2972-2981. [PMID: 28165216 DOI: 10.1021/acs.est.6b05529] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Chlorination has long been used for disinfection of municipal wastewater (MWW) effluent while the use peracetic acid (PAA) has been proposed more recently in the United States. Previous work has demonstrated the bactericidal effectiveness of PAA and monochloramine in wastewater, but limited information is available for viruses, especially ones of mammalian origin (e.g., norovirus). Therefore, a comparative assessment was performed of the virucidal efficacy of PAA and monochloramine against murine norovirus (MNV) and MS2 bacteriophage in secondary effluent MWW and phosphate buffer (PB). A suite of inactivation kinetic models was fit to the viral inactivation data. Predicted concentration-time (CT) values for 1-log10 MS2 reduction by PAA and monochloramine in MWW were 1254 and 1228 mg-min/L, respectively. The 1-, 2-, and 3-log10 model predicted CT values for MNV viral reduction in MWW were 32, 47, and 69 mg-min/L for PAA and 6, 13, and 28 mg-min/L for monochloramine, respectively. Wastewater treatment plant disinfection practices informed by MS2 inactivation data will likely be protective for public health but may overestimate CT values for reduction of MNV. Additionally, equivalent CT values in PB resulted in greater viral reduction which indicate that viral inactivation data in laboratory grade water may not be generalizable to MWW applications.
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Affiliation(s)
- Nathan Dunkin
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University , Baltimore, Maryland 21205, United States
| | - ShihChi Weng
- JHU/MWH-Stantec Alliance, Johns Hopkins University , Baltimore, Maryland 21205, United States
| | - Kellogg J Schwab
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University , Baltimore, Maryland 21205, United States
- JHU/MWH-Stantec Alliance, Johns Hopkins University , Baltimore, Maryland 21205, United States
| | - James McQuarrie
- Metro Wastewater Reclamation District, Denver Colorado 80229, United States
| | - Kati Bell
- MWH (now part of Stantec), Pasadena, California 91101, United States
| | - Joseph G Jacangelo
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University , Baltimore, Maryland 21205, United States
- JHU/MWH-Stantec Alliance, Johns Hopkins University , Baltimore, Maryland 21205, United States
- MWH (now part of Stantec), Pasadena, California 91101, United States
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32
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McLellan NL, Lee H, Habash MB. Evaluation of propidium monoazide and long-amplicon qPCR as an infectivity assay for coliphage. J Virol Methods 2016; 238:48-55. [PMID: 27744093 DOI: 10.1016/j.jviromet.2016.10.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 08/17/2016] [Accepted: 10/09/2016] [Indexed: 12/21/2022]
Abstract
Standardized and rapid assays for viable viral pathogens are needed to inform human health risk assessments. Conventional qPCR is designed to enumerate the gene copies of an organism in a sample, but does not identify those that originated from a viable pathogen. This study was undertaken to evaluate modified qPCR methods as infectivity assays for the enumeration of infectious MS2 coliphage. Propidium monoazide (PMA) treatment coupled with long-amplicon qPCR assays were assessed for their ability to quantify infectious MS2 in pure cultures and following inactivation by a range of UV light exposures and chlorine doses. The qPCR results were compared to the plaque assay, which was used as the standard to indicate the level of infectious MS2 in each sample. For pure cultures, PMA-qPCR results were not significantly different from the plaque assay (p>0.05). At >4 log inactivation, combined PMA and long-amplicon qPCR assays overestimated the level of infectious MS2 remaining (p<0.05). The most accurate long-amplicon qPCR infectivity assay targeted a 624-bp region at the 5' end of the genome. Modified qPCR approaches may be useful tools to monitor the loss of infectivity as a result of disinfection processes.
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Affiliation(s)
- Nicole L McLellan
- School of Environmental Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Hung Lee
- School of Environmental Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Marc B Habash
- School of Environmental Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
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Zyara AM, Torvinen E, Veijalainen AM, Heinonen-Tanski H. The effect of chlorine and combined chlorine/UV treatment on coliphages in drinking water disinfection. JOURNAL OF WATER AND HEALTH 2016; 14:640-9. [PMID: 27441859 DOI: 10.2166/wh.2016.144] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Chlorine disinfection is a globally used method to ensure the safety of drinking water. However, it has not always been successful against viruses and, therefore, it is important to find new methods to disinfect water. Seventeen different coliphages were isolated from the treated municipal wastewater. These coliphages and MS2 were treated with different dosages of chlorine in drinking water, and a combined chlorine/ultraviolet irradiation treatment for the chlorine-resistant coliphages. Chlorine disinfection with 0.3-0.5 mg/L total chlorine (free Cl-dosage 0.12-0.21 mg/L) for 10 min achieved 2.5-5.7 Log10-reductions for 11 sensitive coliphages. The six most resistant coliphages showed no reduction with these chlorine concentrations. MS2 was intermediate in chlorine resistance, and thus it is not a good indicator for viruses in chlorine disinfection. In the combined treatment total chlorine of 0.05-0.25 mg/L (free Cl-dosage 0.02-0.08 mg/L) and ultraviolet irradiation (14-22 mWs/cm(2)) were more effective than chlorine alone, and 3-5 Log10-reductions were achieved for the chlorine-resistant strains. The chlorination efficiency could be increased by higher dosages and longer contact times, but this could increase the formation of disinfection by-products. Therefore, the combination treatment is a recommended disinfection method.
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Affiliation(s)
- Alyaa M Zyara
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 1627, FI 70211 Kuopio, Finland E-mail: ; Department of Biology, University of Baghdad, College of Sciences for Women, Baghdad, Iraq
| | - Eila Torvinen
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 1627, FI 70211 Kuopio, Finland E-mail:
| | - Anna-Maria Veijalainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 1627, FI 70211 Kuopio, Finland E-mail:
| | - Helvi Heinonen-Tanski
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 1627, FI 70211 Kuopio, Finland E-mail:
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Pelleieux S, Mathieu L, Block JC, Gantzer C, Bertrand I. The effect of chlorination and hydrodynamic shear stress on the persistence of bacteriophages associated with drinking water biofilms. J Appl Microbiol 2016; 121:1189-97. [PMID: 27452787 DOI: 10.1111/jam.13243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 07/20/2016] [Accepted: 07/21/2016] [Indexed: 11/30/2022]
Abstract
AIMS This work aimed to assess at pilot scale the effect of chlorination and water flushing on 2-month-old drinking water biofilms and, above all, on biofilm-associated F-specific RNA bacteriophages MS2, GA and Qβ. METHODS AND RESULTS Chlorination (4 mg l(-1) ) was applied first with a hydrodynamic shear stress of 1 Pa and second with an increase in hydrodynamic shear stress to 10 Pa. Despite a rapid decrease in the number of biofilm bacteria and associated phages, infectious phages were still detected on surfaces after completion of the 150 min cleaning procedure. The resulting sequence of phage removal was: GA > Qβ ≫ MS2. CONCLUSIONS The effect of chlorine on biofilm bacteria and biofilm-associated phages was limited to the upper layers of the biofilm and was not enhanced by an increase in hydrodynamic shear stress. A smaller decrease was observed for MS2 than for GA or Qβ after completion of the cleaning procedure. SIGNIFICANCE AND IMPACT OF THE STUDY The differences observed between the three phages suggest that the location of the viral particles in the biofilm, which is related to their surface properties, affects the efficiency of chlorine disinfection.
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Affiliation(s)
- S Pelleieux
- CNRS, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Institut Jean Barriol, Nancy, France.,LCPME, UMR 7564, Université de Lorraine, Nancy, France
| | - L Mathieu
- CNRS, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Institut Jean Barriol, Nancy, France.,EPHE, UL, CNRS, UMR 7564 LCPME, PSL Research University, Nancy, France
| | - J-C Block
- CNRS, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Institut Jean Barriol, Nancy, France.,LCPME, UMR 7564, Université de Lorraine, Nancy, France
| | - C Gantzer
- CNRS, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Institut Jean Barriol, Nancy, France.,LCPME, UMR 7564, Université de Lorraine, Nancy, France
| | - I Bertrand
- CNRS, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Institut Jean Barriol, Nancy, France. .,LCPME, UMR 7564, Université de Lorraine, Nancy, France.
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35
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Verani M, Di Giuseppe G, Tammaro C, Carducci A. Investigating the role of Acanthamoeba polyphaga in protecting Human Adenovirus from water disinfection treatment. Eur J Protistol 2016; 54:11-8. [DOI: 10.1016/j.ejop.2016.02.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 02/23/2016] [Accepted: 02/27/2016] [Indexed: 01/16/2023]
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Kahler AM, Cromeans TL, Metcalfe MG, Humphrey CD, Hill VR. Aggregation of Adenovirus 2 in Source Water and Impacts on Disinfection by Chlorine. FOOD AND ENVIRONMENTAL VIROLOGY 2016; 8:148-55. [PMID: 26910058 PMCID: PMC4864101 DOI: 10.1007/s12560-016-9232-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 02/12/2016] [Indexed: 05/21/2023]
Abstract
It is generally accepted that viral particles in source water are likely to be found as aggregates attached to other particles. For this reason, it is important to investigate the disinfection efficacy of chlorine on aggregated viruses. A method to produce adenovirus particle aggregation was developed for this study. Negative stain electron microscopy was used to measure aggregation before and after addition of virus particles to surface water at different pH and specific conductance levels. The impact of aggregation on the efficacy of chlorine disinfection was also examined. Disinfection experiments with human adenovirus 2 (HAdV2) in source water were conducted using 0.2 mg/L free chlorine at 5 °C. Aggregation of HAdV2 in source water (≥3 aggregated particles) remained higher at higher specific conductance and pH levels. However, aggregation was highly variable, with the percentage of particles present in aggregates ranging from 43 to 71 %. Upon addition into source water, the aggregation percentage dropped dramatically. On average, chlorination CT values (chlorine concentration in mg/L × time in min) for 3-log10 inactivation of aggregated HAdV2 were up to three times higher than those for dispersed HAdV2, indicating that aggregation reduced the disinfection rate. This information can be used by water utilities and regulators to guide decision making regarding disinfection of viruses in water.
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Affiliation(s)
- Amy M Kahler
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, 1600 Clifton Road, Mail Stop D-66, Atlanta, GA, 30329, USA.
| | - Theresa L Cromeans
- Centers for Disease Control and Prevention, National Center for Immunization and Respiratory Diseases, Atlanta, USA
| | - Maureen G Metcalfe
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, 1600 Clifton Road, Mail Stop D-66, Atlanta, GA, 30329, USA
| | - Charles D Humphrey
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, 1600 Clifton Road, Mail Stop D-66, Atlanta, GA, 30329, USA
| | - Vincent R Hill
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, 1600 Clifton Road, Mail Stop D-66, Atlanta, GA, 30329, USA
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37
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Cesa M, Fongaro G, Barardi CRM. Waterborne diseases classification and relationship with social-environmental factors in Florianópolis city - Southern Brazil. JOURNAL OF WATER AND HEALTH 2016; 14:340-8. [PMID: 27105418 DOI: 10.2166/wh.2015.266] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
This study aimed to investigate and classify the occurrence of waterborne diseases in Florianópolis city, Santa Catarina State, Southern Brazil and to correlate these diseases with the following social-environmental indicators of the local population: type of water supply, adequate collection and sewage treatment, areas of flooding and domestic water tank cleaning. Reports of outpatients were analyzed for surveillance of waterborne diseases during the period of 2002 to 2009. Waterborne diseases were classified into four groups: Group A: diarrheal diseases; Group B: parasitological diseases; Group C: skin diseases and Group D: eye diseases. The diarrheal, parasitological and skin diseases were the most frequently reported. Waterborne diseases belonging to Group A in all sites were correlated with other waterborne diseases groups, which can be an indicator of the circulation of other waterborne diseases. Regarding the social-environmental indicators assessed, the most correlated with waterborne diseases were the origin and quality of the water supply, followed by inadequate collection and treatment of sewage, frequent flooding, and finally the lack of cleanliness of the water reservoir. The results highlight the need for policies aiming for improvement of the sanitation service in the maintenance of human, animal and environmental health.
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Affiliation(s)
- M Cesa
- Centro de Filosofia e Ciências Humanas, Departamento de Geociências, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, Santa Catarina State, Brazil
| | - G Fongaro
- Laboratório de Virologia Aplicada, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, Santa Catarina State, Brazil E-mail:
| | - C R M Barardi
- Laboratório de Virologia Aplicada, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, Santa Catarina State, Brazil E-mail:
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Gall AM, Shisler JL, Mariñas BJ. Characterizing Bacteriophage PR772 as a Potential Surrogate for Adenovirus in Water Disinfection: A Comparative Analysis of Inactivation Kinetics and Replication Cycle Inhibition by Free Chlorine. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:2522-2529. [PMID: 26820824 DOI: 10.1021/acs.est.5b04713] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Elucidating mechanisms by which pathogenic waterborne viruses become inactivated by drinking water disinfectants would facilitate the development of sensors to detect infectious viruses and novel disinfection strategies to provide safe water. Using bacteriophages as surrogates for human pathogenic viruses could assist in elucidating these mechanisms; however, an appropriate viral surrogate for human adenovirus (HAdV), a medium-sized virus with a double-stranded DNA genome, needs to be identified. Here, we characterized the inactivation kinetics of bacteriophage PR772, a member of the Tectiviridae family with many similarities in structure and replication to HAdV. The inactivation of PR772 and HAdV by free chlorine had similar kinetics that could be represented with a model previously developed for HAdV type 2 (HAdV-2). We developed and tested a quantitative assay to analyze several steps in the PR772 replication cycle to determine if both viruses being inactivated at similar rates resulted from similar replication cycle events being inhibited. Like HAdV-2, we observed that PR772 inactivated by free chlorine still attached to host cells, and viral DNA synthesis and early and late gene transcription were inhibited. Consequently, free chlorine exposure inhibited a replication cycle event that was post-binding but took place prior to early gene synthesis for both PR772 and HAdV-2.
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Affiliation(s)
- Aimee M Gall
- Department of Civil and Environmental Engineering, ‡Department of Microbiology and College of Medicine, and §Safe Global Water Institute, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Joanna L Shisler
- Department of Civil and Environmental Engineering, ‡Department of Microbiology and College of Medicine, and §Safe Global Water Institute, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Benito J Mariñas
- Department of Civil and Environmental Engineering, ‡Department of Microbiology and College of Medicine, and §Safe Global Water Institute, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
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The efficacy of EO waters on inactivating norovirus and hepatitis A virus in the presence of organic matter. Food Control 2016. [DOI: 10.1016/j.foodcont.2015.09.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Birmpa A, Bellou M, Kokkinos P, Vantarakis A. Effect of Nonthermal, Conventional, and Combined Disinfection Technologies on the Stability of Human Adenoviruses as Fecal Contaminants on Surfaces of Fresh Ready-to-Eat Products. J Food Prot 2016; 79:454-62. [PMID: 26939656 DOI: 10.4315/0362-028x.jfp-15-013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Over one-half of foodborne diseases are believed to be of viral origin. The ability of viruses to persist in the environment and fresh produce, as well as their low infectious dose, allows even a small amount of contamination to cause serious foodborne problems. Moreover, the consumer's demands for fresh, convenient, and safe foods have prompted research into alternative food disinfection technologies. Our study focuses on viral inactivation by both conventional and alternative nonthermal disinfection technologies on different fresh ready-to-eat food products. The use of chlorine, as well as that of nonthermal technologies such as UV light and ultrasound (US), was tested for different treatment times. UV nonthermal technology was found to be more effective for the disinfection of human adenoviruses (hAdVs) compared with US, achieving a log reduction of 2.13, 1.25, and 0.92 for lettuce, strawberries, and cherry tomatoes, respectively, when UV treatment was implemented for 30 min. US treatment for the same period achieved a log reduction of 0.85, 0.53, and 0.36, respectively. The sequential use of US and UV was found to be more effective compared with when the treatments were used separately, for the same treatment time, thus indicating a synergistic effect. In addition, human adenoviruses were inactivated sooner, when chlorine treatment was used. Therefore, the effect of each disinfection method was dependent upon the treatment time and the type of food.
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Affiliation(s)
- Angeliki Birmpa
- Environmental Microbiology Unit, Department of Public Health, Medical School, University of Patras, Patras 26504, Greece
| | - Maria Bellou
- Environmental Microbiology Unit, Department of Public Health, Medical School, University of Patras, Patras 26504, Greece
| | - Petros Kokkinos
- Environmental Microbiology Unit, Department of Public Health, Medical School, University of Patras, Patras 26504, Greece
| | - Apostolos Vantarakis
- Environmental Microbiology Unit, Department of Public Health, Medical School, University of Patras, Patras 26504, Greece.
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Nilsen V, Wyller J. QMRA for Drinking Water: 2. The Effect of Pathogen Clustering in Single-Hit Dose-Response Models. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2016; 36:163-181. [PMID: 26812258 DOI: 10.1111/risa.12528] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Spatial and/or temporal clustering of pathogens will invalidate the commonly used assumption of Poisson-distributed pathogen counts (doses) in quantitative microbial risk assessment. In this work, the theoretically predicted effect of spatial clustering in conventional "single-hit" dose-response models is investigated by employing the stuttering Poisson distribution, a very general family of count distributions that naturally models pathogen clustering and contains the Poisson and negative binomial distributions as special cases. The analysis is facilitated by formulating the dose-response models in terms of probability generating functions. It is shown formally that the theoretical single-hit risk obtained with a stuttering Poisson distribution is lower than that obtained with a Poisson distribution, assuming identical mean doses. A similar result holds for mixed Poisson distributions. Numerical examples indicate that the theoretical single-hit risk is fairly insensitive to moderate clustering, though the effect tends to be more pronounced for low mean doses. Furthermore, using Jensen's inequality, an upper bound on risk is derived that tends to better approximate the exact theoretical single-hit risk for highly overdispersed dose distributions. The bound holds with any dose distribution (characterized by its mean and zero inflation index) and any conditional dose-response model that is concave in the dose variable. Its application is exemplified with published data from Norovirus feeding trials, for which some of the administered doses were prepared from an inoculum of aggregated viruses. The potential implications of clustering for dose-response assessment as well as practical risk characterization are discussed.
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Affiliation(s)
- Vegard Nilsen
- Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, N-1432 Aas, Norway
| | - John Wyller
- Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, N-1432 Aas, Norway
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Fongaro G, Padilha J, Schissi CD, Nascimento MA, Bampi GB, Viancelli A, Barardi CRM. Human and animal enteric virus in groundwater from deep wells, and recreational and network water. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:20060-6. [PMID: 26300358 DOI: 10.1007/s11356-015-5196-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 08/10/2015] [Indexed: 04/16/2023]
Abstract
This study was designed to assess the presence of human adenovirus (HAdV), rotavirus-A (RVA), hepatitis A virus (HAV), and porcine circovirus-2 (PCV2) in groundwater from deep wells, and recreational and network waters. The water samples were collected and concentrated and the virus genomes were assessed and quantified by quantitative PCR (qPCR). Infectious HAdV was evaluated in groundwater and network water samples by integrated cell culture using transcribed messenger RNA (mRNA) (ICC-RT-qPCR). In recreational water samples, HAdV was detected in 100 % (6/6), HAV in 66.6 % (4/6), and RVA in 66.6 % (4/6). In network water, HAdV was detected in 100 % (6/6) of the samples (these 83 % contained infectious HAdV), although HAV and RVA were not detected and PCV2 was not evaluated. In groundwater from deep wells, during rainy period, HAdV and RVA were detected in 80 % (4/5) of the samples, and HAV and PCV2 were not detected; however, during dry period, HAdV and RVA were detected in 60 % (3/5), HAV in only one sample, and PCV2 in 60 % (4/5). In groundwater, all samples contained infectious HAdV. PCV2 presence in groundwater is indicative of contamination caused by swine manure in Concórdia, Santa Catarina, Brazil. The disinfection of human and animal wastes is urgent, since they can contaminate surface and groundwater, being a potential threat for public and animal health.
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Affiliation(s)
- Gislaine Fongaro
- Laboratório de Virologia Aplicada, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
| | - J Padilha
- Laboratório de Análise Ambiental, Fundação Universidade do Contestado, Concórdia, SC, 89700-000, Brazil
| | - C D Schissi
- Laboratório de Virologia Aplicada, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil
| | - M A Nascimento
- Laboratório de Virologia Aplicada, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil
| | - G B Bampi
- Laboratório de Análise Ambiental, Fundação Universidade do Contestado, Concórdia, SC, 89700-000, Brazil
| | - A Viancelli
- Laboratório de Análise Ambiental, Fundação Universidade do Contestado, Concórdia, SC, 89700-000, Brazil
| | - C R M Barardi
- Laboratório de Virologia Aplicada, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil
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Leifels M, Jurzik L, Wilhelm M, Hamza IA. Use of ethidium monoazide and propidium monoazide to determine viral infectivity upon inactivation by heat, UV- exposure and chlorine. Int J Hyg Environ Health 2015; 218:686-93. [DOI: 10.1016/j.ijheh.2015.02.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 02/08/2015] [Accepted: 02/09/2015] [Indexed: 01/06/2023]
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Sokolova E, Petterson SR, Dienus O, Nyström F, Lindgren PE, Pettersson TJR. Microbial risk assessment of drinking water based on hydrodynamic modelling of pathogen concentrations in source water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 526:177-186. [PMID: 25931024 DOI: 10.1016/j.scitotenv.2015.04.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 04/01/2015] [Accepted: 04/12/2015] [Indexed: 06/04/2023]
Abstract
Norovirus contamination of drinking water sources is an important cause of waterborne disease outbreaks. Knowledge on pathogen concentrations in source water is needed to assess the ability of a drinking water treatment plant (DWTP) to provide safe drinking water. However, pathogen enumeration in source water samples is often not sufficient to describe the source water quality. In this study, the norovirus concentrations were characterised at the contamination source, i.e. in sewage discharges. Then, the transport of norovirus within the water source (the river Göta älv in Sweden) under different loading conditions was simulated using a hydrodynamic model. Based on the estimated concentrations in source water, the required reduction of norovirus at the DWTP was calculated using quantitative microbial risk assessment (QMRA). The required reduction was compared with the estimated treatment performance at the DWTP. The average estimated concentration in source water varied between 4.8×10(2) and 7.5×10(3) genome equivalents L(-1); and the average required reduction by treatment was between 7.6 and 8.8 Log10. The treatment performance at the DWTP was estimated to be adequate to deal with all tested loading conditions, but was heavily dependent on chlorine disinfection, with the risk of poor reduction by conventional treatment and slow sand filtration. To our knowledge, this is the first article to employ discharge-based QMRA, combined with hydrodynamic modelling, in the context of drinking water.
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Affiliation(s)
- Ekaterina Sokolova
- Chalmers University of Technology, Department of Civil and Environmental Engineering, Water Environment Technology, SE-412 96 Gothenburg, Sweden.
| | - Susan R Petterson
- Norwegian University of Life Sciences NMBU, Department of Mathematical Sciences and Technology, P.O. Box 5003, NO-1432 Ås, Norway; Water & Health Pty Ltd. P.O. Box 648 Salamander Bay, 2317, Australia
| | - Olaf Dienus
- Ryhov County Hospital, Medical Services, Clinical Microbiology, SE-551 85 Jönköping, Sweden
| | - Fredrik Nyström
- Ryhov County Hospital, Medical Services, Clinical Microbiology, SE-551 85 Jönköping, Sweden; Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology, SE-581 85 Linköping, Sweden
| | - Per-Eric Lindgren
- Ryhov County Hospital, Medical Services, Clinical Microbiology, SE-551 85 Jönköping, Sweden; Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology, SE-581 85 Linköping, Sweden
| | - Thomas J R Pettersson
- Chalmers University of Technology, Department of Civil and Environmental Engineering, Water Environment Technology, SE-412 96 Gothenburg, Sweden
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Petterson SR, Stenström TA. Quantification of pathogen inactivation efficacy by free chlorine disinfection of drinking water for QMRA. JOURNAL OF WATER AND HEALTH 2015; 13:625-644. [PMID: 26322749 DOI: 10.2166/wh.2015.193] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
To support the implementation of quantitative microbial risk assessment (QMRA) for managing infectious risks associated with drinking water systems, a simple modeling approach for quantifying Log10 reduction across a free chlorine disinfection contactor was developed. The study was undertaken in three stages: firstly, review of the laboratory studies published in the literature; secondly, development of a conceptual approach to apply the laboratory studies to full-scale conditions; and finally implementation of the calculations for a hypothetical case study system. The developed model explicitly accounted for variability in residence time and pathogen specific chlorine sensitivity. Survival functions were constructed for a range of pathogens relying on the upper bound of the reported data transformed to a common metric. The application of the model within a hypothetical case study demonstrated the importance of accounting for variable residence time in QMRA. While the overall Log10 reduction may appear high, small parcels of water with short residence time can compromise the overall performance of the barrier. While theoretically simple, the approach presented is of great value for undertaking an initial assessment of a full-scale disinfection contactor based on limited site-specific information.
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Affiliation(s)
- S R Petterson
- Water & Health Pty Ltd, P.O. Box 648, Salamander Bay 2317, Australia and Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Ås, Norway E-mail:
| | - T A Stenström
- Durban University of Technology, SARChi Chair, Institute for Water and Wastewater Technology, Durban University of Technology, P.O. Box 1334, Durban 4000, South Africa
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Rattanakul S, Oguma K, Takizawa S. Sequential and Simultaneous Applications of UV and Chlorine for Adenovirus Inactivation. FOOD AND ENVIRONMENTAL VIROLOGY 2015; 7:295-304. [PMID: 26006252 DOI: 10.1007/s12560-015-9202-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 05/16/2015] [Indexed: 06/04/2023]
Abstract
Adenoviruses are water-borne human pathogens with high resistance to UV disinfection. Combination of UV treatment and chlorination could be an effective approach to deal with adenoviruses. In this study, human adenovirus 5 (HAdV-5) was challenged in a bench-scale experiment by separate applications of UV or chlorine and by combined applications of UV and chlorine in either a sequential or simultaneous manner. The treated samples were then propagated in human lung carcinoma epithelial cells to quantify the log inactivation of HAdV-5. When the processes were separate, a fluence of 100 mJ/cm(2) and a CT value of 0.02 mg min/L were required to achieve 2 log inactivation of HAdV-5 by UV disinfection and chlorination, respectively. Interestingly, synergistic effects on the HAdV-5 inactivation rates were found in the sequential process of chlorine followed by UV (Cl2-UV) (p < 0.05, ANCOVA) in comparison to the separate processes or the simultaneous application of UV/Cl2. This implies that a pretreatment with chlorine may increase the sensitivity of the virus to the subsequent UV disinfection. In conclusion, this study suggests that the combined application of UV and chlorine could be an effective measure against adenoviruses as a multi-barrier approach in water disinfection.
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Affiliation(s)
- Surapong Rattanakul
- Department of Urban Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
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Cervero-Aragó S, Rodríguez-Martínez S, Puertas-Bennasar A, Araujo RM. Effect of Common Drinking Water Disinfectants, Chlorine and Heat, on Free Legionella and Amoebae-Associated Legionella. PLoS One 2015; 10:e0134726. [PMID: 26241039 PMCID: PMC4524690 DOI: 10.1371/journal.pone.0134726] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 07/13/2015] [Indexed: 12/12/2022] Open
Abstract
Chlorine and thermal treatments are the most commonly used procedures to control and prevent Legionella proliferation in drinking water systems of large buildings. However, cases of legionellosis still occur in facilities with treated water. The purpose of this work was to model the effect of temperature and free chlorine applied in similar exposure conditions as in drinking water systems on five Legionella spp. strains and two amoebal strains of the genera Acanthamoeba. Inactivation models obtained were used to determine the effectiveness of the treatments applied which resulted more effective against Legionella than Acanthamoeba, especially those in cystic stages. Furthermore, to determine the influence of the relationship between L. pneumophila and Acanthamoeba spp. on the treatment effectiveness, inactivation models of the bacteria-associated amoeba were also constructed and compared to the models obtained for the free living bacteria state. The Legionella-amoeba association did not change the inactivation models, but it reduced the effectiveness of the treatments applied. Remarkably, at the lowest free chlorine concentration, 0.5 mg L-1, as well as at the lowest temperatures, 50°C and 55°C, the influence of the Legionella-amoeba associate state was the strongest in reducing the effectiveness of the treatments compared to the free Legionella state. Therefore, the association established between L. pneumophila and amoebae in the water systems indicate an increased health risk in proximal areas of the system (close to the tap) where lower free chlorine concentrations and lower temperatures are commonly observed.
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Affiliation(s)
- Sílvia Cervero-Aragó
- Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
- Water Hygiene, Institute for Hygiene and Applied Immunology, Medical University of Vienna, Kinderspitalgasse 15, A-1090, Vienna, Austria
| | - Sarah Rodríguez-Martínez
- Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
- Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa, Oranim, 36006, Tivon, Israel
| | - Antoni Puertas-Bennasar
- Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
| | - Rosa M. Araujo
- Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
- * E-mail:
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48
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Osuolale O, Okoh A. Incidence of human adenoviruses and Hepatitis A virus in the final effluent of selected wastewater treatment plants in Eastern Cape Province, South Africa. Virol J 2015; 12:98. [PMID: 26104284 PMCID: PMC4481066 DOI: 10.1186/s12985-015-0327-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 06/16/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Municipal effluent constitutes a large reservoir of human enteric viruses and bacteria. Contemporary monitoring practices rely on indicator bacteria, and do not test for viruses. Different viruses, including Norwalk-like viruses, Hepatitis A virus (HAV), adenoviruses, and rotaviruses, are important agents of illnesses in humans. The burden of disease caused by adenoviruses manifests as pneumonia, bronchiolitis, otitis media, conjunctivitis, and tonsillitis, whereas HAV infection can manifest as acute inflammatory diseases of the liver, fever, anorexia, malaise, nausea, and abdominal discomfort, followed by jaundice and dark urine. The public health implications of these viruses depend upon the physiological status of the wastewater microbial community. METHODS The occurrence of human adenovirus (HAdV) and HAV was determined in the final effluents of five wastewater treatment plants (WWTPs) in the Eastern Cape, South Africa, over 12 months (September 2012-August 2013). The viruses were detected with real-time PCR, and conventional PCR was used for serotyping. RESULTS Adenovirus was detected in effluent samples from all five WWTPs and in 64 % of the total samples, whereas HAV was not detected in any effluent sample. At WWPT-A, samples were collected from the final effluent tank (adenoviral concentrations ranged from 1.05 × 10(1) to 1.10 × 10(4) genome/L, with a 41.7 % detection rate) and the discharge point (adenoviral concentrations ranged between 1.2 × 10(1) and 2.8 × 10(4) genome/L, with a 54.5 % detection rate). At WWPT-B, HAdV was detected in 91.7 % of samples, with viral concentrations of 7.92 × 10(1)-2.37 × 10(5) genome/L. The HAdV concentrations at WWPT-C were 5.32 × 10(1)-2.20 × 10(5) genome/L, and the detection rate was 75 %. The adenoviral concentrations at WWPT-D were 1.23 × 10(3)-1.05 × 10(4) genome/L, and the detection rate was 66.7 %. At WWPT-E, the viral concentrations were 1.08 × 10(1)-5.16 × 10(4) genome/L, and the detection rate was 54.5 %. Characterization of the adenoviruses revealed HAdV serotypes 2 (1.4 %) and 41 (7.1 %), in species C and F, respectively. CONCLUSIONS This study is the first to report the prevalence of HAdV in the final effluents of WWTPs in the Eastern Cape, South Africa. The adenoviral detection rates indicate the potential contamination of the environment, with adverse effects on public health.
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Affiliation(s)
- Olayinka Osuolale
- SA-MRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, 5700, South Africa. .,Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice, 5700, South Africa.
| | - Anthony Okoh
- SA-MRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, 5700, South Africa.,Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice, 5700, South Africa
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Gall AM, Shisler JL, Mariñas BJ. Analysis of the viral replication cycle of adenovirus serotype 2 after inactivation by free chlorine. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:4584-4590. [PMID: 25756747 DOI: 10.1021/acs.est.5b00301] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Free chlorine is effective at inactivating a wide range of waterborne viral pathogens including human adenovirus (HAdV), but the mechanisms by which free chlorine inactivates HAdV and other human viruses remain to be elucidated. Such advances in fundamental knowledge are key for development of new disinfection technologies and novel sensors to detect infectious viruses in drinking water. We developed and tested a quantitative assay to analyze several steps in the HAdV replication cycle upon increasing free chlorine exposure. We used quantitative polymerase chain reaction (qPCR) to detect HAdV genomic DNA as a means to quantify attachment and genome replication of untreated and treated virions. Also, we used quantitative reverse-transcription PCR (RT-qPCR) to quantify the transcription of E1A (first early protein) and hexon mRNA. We compared these replication cycle events to virus inactivation kinetics to determine what stage of the virus replication cycle was inhibited as a function of free chlorine exposure. We observed that adenovirus inactivated at levels up to 99.99% by free chlorine still attached to host cells; however, viral DNA synthesis and early E1A and late hexon gene transcription were inhibited. We conclude that free chlorine exposure interferes with a replication cycle event occurring postbinding but prior to early viral protein synthesis.
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Affiliation(s)
- Aimee M Gall
- †Department of Civil and Environmental Engineering, ‡Department of Microbiology and College of Medicine, and §Safe Global Water Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Joanna L Shisler
- †Department of Civil and Environmental Engineering, ‡Department of Microbiology and College of Medicine, and §Safe Global Water Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Benito J Mariñas
- †Department of Civil and Environmental Engineering, ‡Department of Microbiology and College of Medicine, and §Safe Global Water Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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Nascimento MA, Magri ME, Schissi CD, Barardi CR. Recombinant adenovirus as a model to evaluate the efficiency of free chlorine disinfection in filtered water samples. Virol J 2015; 12:30. [PMID: 25889833 PMCID: PMC4349469 DOI: 10.1186/s12985-015-0259-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 02/03/2015] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND In Brazil, ordinance no. 2,914/2011 of the Ministry of Health requires the absence of total coliforms and Escherichia coli (E. coli) in treated water. However it is essential that water treatment is effective against all pathogens. Disinfection in Water Treatment Plants (WTP) is commonly performed with chlorine. METHODS The recombinant adenovirus (rAdV), which expresses green fluorescent protein (GFP) when cultivated in HEK 293A cells, was chosen as a model to evaluate the efficiency of chlorine for human adenovirus (HAdV) inactivation in filtered water samples from two WTPs: Lagoa do Peri (pH 6.9) and Morro dos Quadros (pH 6.5). Buffered demand free (BDF) water (pH 6.9 and 8.0) was used as control. The samples were previously submitted to physicochemical characterization, and bacteriological analysis. Two free chlorine concentrations and two temperatures were assayed for all samples (0.2 mg/L, 0.5 mg/L, and 15°C, and 20°C). Fluorescence microscopy (FM) was used to check viral infectivity in vitro and qPCR as a molecular method to determine viral genome copies. Real treated water samples from the WTP (at the output of WTP and the distribution network) were also evaluated for total coliforms, E. coli and HAdV. RESULTS The time required to inactivate 4log₁₀ of rAdV was less than 1 min, when analyzed by FM, except for BDF pH 8.0 (up to 2.5 min for 4log₁₀). The pH had a significant influence on the efficiency of disinfection. The qPCR assay was not able to provide information regarding rAdV inactivation. The data were modeled (Chick-Watson), and the observed Ct values were comparable with the values reported in the literature and smaller than the values recommended by the EPA. In the treated water samples, HAdV was detected in the distribution network of the WTP Morro dos Quadros (2.75 × 10(3) PFU/L). CONCLUSION The Chick-Watson model proved to have adjusted well to the experimental conditions used, and it was possible to prove that the adenoviruses were rapidly inactivated in the surface water treated with chlorine and that the recombinant adenovirus expressing GFP is a good model for this evaluation.
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Affiliation(s)
- Mariana A Nascimento
- Laboratório de Virologia Aplicada, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, Santa Catarina, Brazil.
| | - Maria E Magri
- Laboratório de Virologia Aplicada, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, Santa Catarina, Brazil.
| | - Camila D Schissi
- Laboratório de Virologia Aplicada, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, Santa Catarina, Brazil.
| | - Célia Rm Barardi
- Laboratório de Virologia Aplicada, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, Santa Catarina, Brazil.
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